The researchers found that from baseline to 18 weeks, dark chocolate intake reduced average systolic BP by −2.9 (1.6) mm Hg and diastolic BP by −1.9 (1.0) mm Hg without changes in body weight, plasma levels of lipids or glucose. Hypertension prevalence declined from 86 percent to 68 percent. Systolic and diastolic BP remained unchanged throughout the treatment period among those in the white chocolate group. Dark chocolate consumption resulted in the short-term appearance of cocoa phenols in plasma and increased vasodilatory S-nitrosoglutathione. There was no change in plasma biomarkers in the white chocolate group.

“Although the magnitude of the BP reduction was small, the effects are clinically noteworthy. On a population basis, it has been estimated that a 3-mm Hg reduction in systolic BP would reduce the relative risk of stroke mortality by eight percent, of coronary artery disease mortality by five percent, and of all-cause mortality by four percent,” the authors write.

“The most intriguing finding of this study is that small amounts of commercial cocoa confectionary convey a similar BP-lowering potential compared with comprehensive dietary modifications that have proven efficacy to reduce cardiovascular event rate,” the authors conclude.